Breathing and Exchange of Gases

The partial pressures (in mm Hg) of oxygen (O2) and carbon dioxide (CO2) at alveoli (the site of diffusion) are :

1. pO2 = 159 and pCO2 = 0.3
2. pO2 = 104 and pCO2 = 40
3. pO2 = 40 and pCO2 = 45
4. pO2 = 95 and pCO2 = 40

Select the correct events that occur during inspiration.

1. Only (iv)
2. (iii) and (iv)
3. (i), (ii) and (iv)
4. (i) and (ii)

Identify the wrong statement with reference to transport of oxygen.

1. Binding of oxygen with haemoglobin is mainly related to partial pressure of O2
2. Partial pressure of CO2 can interfere with O2 binding with haemoglobin
3. Higher H+ conc. in alveoli favours the formation of oxyhaemoglobin
4. Low pCO2 in alveoli favours the formation of oxyhaemoglobin

Tidal Volume and Expiratory Reserve Volume of an athlete is 500 mL and 1000 mL respectively. What will be his Expiratory Capacity if the Residual Volume is 1200 mL?

1. 2200 mL
2. 2700 mL
3. 1500 mL
4. 1700 mL

Due to increasing air-borne allergens and pollutants, many people in urban areas are suffering from respiratory disorder causing wheezing due to :

1. Proliferation of fibrous tissues and damage of the alveolar walls
2. Reduction in the secretion of surfactants by pneumocytes
3. Benign growth on mucous lining of nasal cavity
4. Inflammation of bronchi and bronchioles

Which of the following options correctly represents the lung conditions in asthma and emphysema, respectively?

1. Decreased respiratory surface; Inflammation of bronchioles
2. Inflammation of bronchioles; Decreased respiratory surface
3. Increased number of bronchioles; Increased respiratory surface
4. Increased respiratory surface; Inflammation of bronchioles

Match the items given in column I with those in column II and select the correct option given below.

1. (a)-(iii), (b)-(i), (c)-(iv), (d)-(ii)
2. (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
3. (a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)
4. (a)-(i), (b)-(iv), (c)-(ii), (d)-(iii)

Which of the following is an occupational respiratory disorder?

1. Botulism
2. Anthracis
3. Silicosis
4. Emphysema

Lungs are made up of air-filled sacs, the alveoli. They do not collapse even after forceful expiration, because of

1. inspiratory reserve volume
2. tidal volume
3. expiratory reserve volume
4. residual volume.

Reduction in pH of blood will

1. decrease the affinity of haemoglobin with oxygen
2. release bicarbonate ions by the liver
3. reduce the rate of heart beat
4. reduce the blood supply to the brain.